Neuromodulation, such as deep brain stimulation, is becoming an increasingly preferred form of therapy for certain neurological conditions and disorders. Currently, deep brain stimulation of the subthalamic nucleus and the globus pallidus interna is approved for treatment of Parkinson's disease and deep brain stimulation of the ventral intermediate nucleus is approved for treatment of essential tremor. Other target sites in the brain to treat additional disorders are also contemplated. For example, as described in U.S. Pat. No. 5,938,688 and U.S. Pat. No. 6,167,311, respectively, the intralaminar nuclei of the thalamus could be stimulated to treat patients with impaired cognitive function and/or patients with psychological disorders.
Current electrical leads used in deep brain stimulation, however, do not provide precise targeting of the areas of the thalamus such as the intralaminar nuclei, such that the desired volume of tissue is stimulated. Accordingly, there is a need in the art for a stimulation device that precisely targets specific regions of the thalamus, maximizes stimulation of these specific regions and minimizes stimulation of adjacent tissue that results in undesirable side effects.